SYF Mainboard 315-5378
This is a brand-new manufactured replacement mainboard compatible with your Sega Game Gear, using all new components. The board makes it possible to repair your VA0 (dual-ASIC) model Game Gear which suffers from PCB damage caused by leaking capacitors or batteries.
The board has been reverse engineered from a Sega Game Gear VA0 model, better known as the dual-ASIC variant. Since I am not able to source new ASIC chips, cartridge connectors and expansion port connections, you need to supply these parts from one of your broken boards.
Recommended tools are:
The following table can be used to connect a LCD kit to the mainboard:
- Soldering iron with 1-1.5mm chisel tip
- Hot air rework station
- Desoldering gun or pump
- Flux
- IPA
- Multimeter and/or oscilloscope
- Source broken Sega Game Gear dual-ASIC mainboard; working chips are:
- IC1 Toshiba 84C00AM-6
- IC2 SEGA 315-5377 VDP ASIC
- IC3 SEGA 315-5378A or 315-5378B SCA ASIC
- Remove cartridge slot and expansion port using de-solder gun
- Remove above chips with hot-air and clean pins with solder wick
- Align the above chips on the new board – it should snug into position using the solder mask
- Tack few pins on the edges
- Apply flux and drag solder all pins of the ASIC – remove solder bridges with solder wick
- Solder XTAL, LED, cartridge connector power and sound cable
- The region is default selected to rest-of-world, in case you want change it to Japanese, switch the small switch next to the audio connector
- Validate installation with starting a game – you should hear game sound
- Install LCD kit
- Assemble the shell
- Enjoy another 30 years of playing on a Game Gear!
The following table can be used to connect a LCD kit to the mainboard:
| MAINBOARD | BennVenn | Cleanscreen | Funnyplaying | GGLCD | MagicScreen | ASIC |
| SMS | SMS | SMS | SMS | MODE | GG/SMS | /GG |
| CLK | CLK | PCLK | CLK | 32M | XTL2 | |
| GND | GROUND | GND | GND | GND | GND | GND |
| RES | RES | VSYNC | DW0 | DW | DW0 | |
| D0 | D0 | D1 | D0 | D1 | D1 | D1 |
| D3 | D3 | D2 | D3 | D4 | D4 | D4 |
| D2 | D2 | D0 | D2 | D3 | D3 | D3 |
| D1 | D1 | D3 | D1 | D2 | D2 | D2 |
| CL2 | CL2 | HSYNC | CL2 | CL2 | CL2 | CL2 |
| 5V | 5V | 5V | VCC | 5V | 5V | VCC |
| BL1 | BRIGHTNESS | WHL+ | P1 | BL1 | - | |
| BTS | 1 | START | BUT3 | START | /PS | |
| BTU | 2 | /UP | ||||
| BTD | 3 | /DW | ||||
| BT1 | BUT1 | /TL | ||||
| BT2 | 2 | BUT2 | BTN2 | /TR | ||
| BTL | LEFT | /LE | ||||
| BTR | /RI | |||||
| CS | CSYNC | CSYNC | CSYNC | CSYNC | ||
| BL2 | WHL- | P2 | N/C | BL2 | - |
In case you install a BennVenn kit – bridge the BV solder pad next to the brightness wheel.
The kit includes:
- Brand new mainboard - all surface mount parts are assembled
- 5-pin contrast wheel
- 9-pin power board cable with AMP CT connector
- 6-pin sound board cable with AMP CT connector
- 32.2160MHz crystal
- 3mm red/green LED - switch polarity if you want a different color
| Name | Value | Package | LCSC Part |
| C4 | 100nF | 0603 | C14663 |
| C5 | 100nF | 0603 | C14663 |
| C6 | 10uF | 0603 | C326057 |
| C7 | 100nF | 0603 | C14663 |
| C8 | 330nF | 0603 | C107070 |
| C9 | 330nF | 0603 | C107070 |
| C10 | 330nF | 0603 | C107070 |
| C11 | 330nF | 0603 | C107070 |
| C12 | 100nF | 0603 | C14663 |
| C14 | 100nF | 0603 | C14663 |
| C15 | 5pF | 0603 | C327203 |
| C16 | 5pF | 0603 | C327203 |
| C17 | 1uF | 1206 | C11363 |
| C18 | 8.2nF | 0603 | C113812 |
| C19 | 100nF | 0603 | C14663 |
| C20 | 1uF | 1206 | C11363 |
| C21 | 1uF | 1206 | C11363 |
| C22 | 8.2nF | 0603 | C113812 |
| C23 | 1uF | 1206 | C11363 |
| C24 | 2.2nF | 0603 | C107082 |
| C25 | 2.2nF | 0603 | C107082 |
| C26 | 2.2nF | 0603 | C107082 |
| C27 | 2.2nF | 0603 | C107082 |
| C28 | 2.2nF | 0603 | C107082 |
| C29 | 2.2nF | 0603 | C107082 |
| C30 | 2.2nF | 0603 | C107082 |
| C48 | 10uF | 0603 | C326057 |
| C49 | 22uF | 0603 | C109447 |
| C51 | 100nF | 0603 | C14663 |
| C59 | 39pF | 0603 | C107049 |
| C60 | 39pF | 0603 | C107049 |
| C61 | 39pF | 0603 | C107049 |
| C62 | 39pF | 0603 | C107049 |
| C73 | 39pF | 0603 | C107049 |
| C74 | 39pF | 0603 | C107049 |
| C75 | 120pF | 0603 | C107035 |
| C76 | 22nF | 0603 | C106222 |
| C82 | 68pF | 0603 | C62782 |
| C83 | 33pF | 0603 | C107047 |
| C84 | 5pF | 0603 | C327203 |
| C85 | 33pF | 0603 | C107047 |
| C86 | 10uF | 0603 | C326057 |
| C87 | 100nF | 0603 | C14663 |
| C89 | 22pF | 0603 | C105620 |
| C90 | 100nF | 0603 | C14663 |
| CN5 | F1004-H-14-20G-R | SMD | C283167 |
| CN6 | F0504-H-10-20T-R | SMD | C283142 |
| CN7 | F0504-H-10-20T-R | SMD | C283142 |
| D4 | PD3S230 | DI323 | C212293 |
| E1 | 2.2nFx2 | 0603 | C96589 |
| E2 | 2.2nFx2 | 0603 | C96589 |
| E3 | 2.2nFx2 | 0603 | C96589 |
| E4 | 2.2nFx2 | 0603 | C96589 |
| E5 | 2.2nFx2 | 0603 | C96589 |
| E6 | 2.2nFx2 | 0603 | C96589 |
| E7 | 2.2nFx2 | 0603 | C96589 |
| E8 | 2.2nFx2 | 0603 | C96589 |
| IC1 | TMP84C00 | SSOP40 | |
| IC2 | 315-5377 | QFP80 | |
| IC3 | 315-5378 | QFP100 | |
| IC3 | HM65256 | SOIC-28 | |
| IC3 | LY6264SL-70LLI | SOIC-28 | C14323 |
| IC4 | LM358 | SOIC-8 | C74525 |
| L1 | 100R@100MHz | 0603 | C142080 |
| L3 | 100uH | 1206 | C165807 |
| R1 | 4.7K | 0603 | C99782 |
| R2 | 4.7K | 0603 | C99782 |
| R3 | 4.7K | 0603 | C99782 |
| R4 | 4.7K | 0603 | C99782 |
| R5 | 4.7K | 0603 | C99782 |
| R6 | 4.7K | 0603 | C99782 |
| R7 | 470K | 0603 | C114622 |
| R8 | 470K | 0603 | C114622 |
| R9 | 470K | 0603 | C114622 |
| R10 | 470K | 0603 | C114622 |
| R11 | 3K | 0603 | C126358 |
| R12 | 4.7K | 0603 | C99782 |
| R13 | 1.8K | 0603 | C185354 |
| R14 | 51R | 0603 | C114628 |
| R20 | 1K | 0603 | C22548 |
| R21 | 1K | 0603 | C22548 |
| R22 | 10K | 0603 | C98220 |
| R23 | 1K | 0603 | C22548 |
| R24 | 1K | 0603 | C22548 |
| R25 | 10K | 0603 | C98220 |
| R26 | 47K | 0603 | C105579 |
| R27 | 47K | 0603 | C105579 |
| R48 | 10K | 0603 | C98220 |
| R49 | 10K | 0603 | C98220 |
| R50 | 9.1K | 0603 | C114639 |
| R51 | 1.1K | 0603 | C137780 |
| R52 | 3K | 0603 | C126358 |
| R54 | 220R | 0603 | C107696 |
| R55 | 220R | 0603 | C107696 |
| R56 | 220R | 0603 | C107696 |
| R57 | 220R | 0603 | C107696 |
| R65 | 1K | 0603 | C22548 |
| R66 | 10K | 0603 | C98220 |
| R67 | 10K | 0603 | C98220 |
| R68 | 3K | 0603 | C126358 |
| SW1 | SSSS811101 | C109335 | |